One of the more widespread skin diseases is Seborrheic dermatitis (hereinafter "SD") [1]. SD results in the shedding of small skin scales and mainly affects the scalp, eyebrows, eyelashes, ears, armpits and other folds in the skin. The shedding of skin scales from the scalp, known as dandruff, can have a serious effect on the aesthetic appearance of a person, and numerous lotions and shampoos are available to treat this affliction.
Although the etiology of this syndrome is not completely clear, recent evidence has indicated that the lipophilic yeast Malassezia furfur (syn. Pityrosporum orbiculare) is associated with this disease [2]. This yeast was also shown to cause fungemia and pulmonary infections in debilitated individuals, and particularly in neonates and adults receiving intralipid [3]. This led to the use of antimycotics, such as ketoconazole, as therapy for SD. However, since ketoconazole is a prescription drug, its use for the treatment of SD has been limited. An inexpensive, non-prescription formulation would therefore be desirable for the treatment of SD.
It is known that the first step in the development of an infection is the adherence of the microorganism to the host's epithelial cells [4]. This has also been confirmed for fungi in general [5], and for the yeast Pityrosporum orbiculare in particular [6].
A few years ago, a substance named chitin soluble extract (hereinafter "CSE") was found to be effective in the prevention of infections caused by yeasts of the genus Candida. CSE is described in U.S. Pat. No. 4,701,444 issued Oct. 20, 1987, whose contents are incorporated herein by reference. CSE was found to interfere with the adherence of Candida to epithelial cells, thus preventing the initiation of infection.
CSE can be prepared from commercially available chitin. The substance is applied topically to various tissues in order to prevent adherence of the pathogenic yeast, thereby reducing the rate of infection.